The present invention is directed to an engine throttle control method for marine applications involving either one or two engines.
There is a desire in the marine industry to utilize engine throttle controls to achieve various automatic operating modes. Such modes include a cruise mode in which the engine throttle is regulated to maintain a selected engine cruising speed, and a sync mode in which a pair of engines are maintained in speed synchronism. Various approaches have been taken for achieving these and other controls, and the control software tends to be very application specific, resulting in a number of different operator interfaces that vary in complexity and ease of use. Additionally, there has been no standard approach for transitioning between automatic and manual operating modes, which can result in unexpected power surging and erratic operation.
The present invention is directed to an improved marine engine throttle control methodology that can be utilized in either single or twin engine applications, and that provides a safe and logical transitioning between manual and automatic operating modes. According to this invention, a standard software instruction set is installed in a microprocessor-based engine control module for each engine, and a discrete input informs the control module if the respective engine is a master engine or a slave engine. In single engine applications, the engine is identified as a master engine, while in twin engine applications, one of the engines is identified as a master engine, and the other as a slave engine. The control software provides an operator activated speed control function for a master engine, and an operator activated sync control function for a slave engine. Each engine has an operator manipulated throttle lever for controlling the respective engine throttle position during the manual operating mode, and for defining a limit throttle position during the automatic operating modes. Transitioning from automatic to manual operating modes occurs when the limit throttle position prevents the automatic control from achieving or maintaining the desired engine speed. A simple panel indicator is provided for each engine, and is activated in a steady mode to indicate complete engagement of the respective automatic mode, and in a pulsed mode to inform the operator that the respective throttle lever is limiting the automatic mode. When the respective throttle lever is sufficiently reduced, the control transitions from automatic mode to manual mode and the respective panel lamp is deactivated.